this combination of serum antibody , mucosal antibody and t-cell responses provides the potential for improved ability to prevent infection and suggests that nasovax could have a greater impact on flu symptoms and containing the spread of the flu virus than currently approved influenza vaccines . all subjects were followed for an additional six months after vaccination to assess the durability of the antibody response , and 8 of the 15 subjects from the highest dose returned between 12 and 14 months after initial dosing for an additional immunogenicity assessment . these new nasovax data on the long-term durability of the immune response show that the immune response elicited by nasovax remained at seroprotective levels for at least 13 months . durable responses on the order of one year are not expected from currently approved influenza vaccines and suggest that the immune response induced by nasovax could be much longer than the current influenza vaccines . 61 nasoshield nasoshield is an anthrax vaccine designed to provide rapid and stable protection after a single intranasal administration . in a head-to-head comparison with the existing approved anthrax vaccine in well-established animal models , a single dose of nasoshield showed complete protection from inhalation anthrax and was non-inferior to multiple doses of the existing approved anthrax vaccine while providing for a more rapid and stable immune response . we have developed the product candidate with the support of the biomedical advanced research and development authority ( “ barda ” ) , and with their continued financial and contractual support , we launched a phase 1 trial of nasoshield in the first quarter of 2018. the purpose of the phase 1 trial was to assess the safety and immunogenicity of a single intranasal dose of nasoshield at four dose cohort levels . an additional cohort received a repeated dose of nasoshield at day 21. based on initial data from the single and two-dose cohorts , nasoshield was well-tolerated but did not produce an appreciable toxin neutralizing antibody ( tna ) response . the company did not expect this result given the compelling nonclinical data obtained previously in two well-established animal models for anthrax . we are investigating all potential causes that may have contributed to these results . the results of these investigations are expected in the first half of 2019. sparvax-l sparvax-l is our alternative anthrax vaccine candidate being developed under contract with niaid . it is a recombinant protein-based anthrax vaccine designed to require fewer doses and have a longer shelf-life than the only currently licensed anthrax vaccine . the shelf life of a liquid formulation was insufficient to meet the government standards and the product was reformulated as a lyophilized ( dry powder ) formulation . we have demonstrated a significant improvement in product stability ( at least two years at room temperature and at least six years at refrigerated temperatures ) with the lyophilized formulation . recent preclinical experiments have shown sparvax-l to be 100 % protective with a two-dose regiment ( 0 and 14 days ) with higher protective toxin neutralizing antibodies than the currently licensed vaccine administered under the same schedule . as of december 31 , 2018 , development activities under the existing niaid contract are substantially complete and the company will only continue development of sparvax-l with the support of the us government or other entity . no such funding has been identified as of the date of this filing . merger with pharmathene our business is the result of a merger between pharmathene , inc. ( “ pharmathene ” ) and the business previously known as altimmune , inc. ( “ private altimmune ” ) . in may 2017 , private altimmune merged with pharmathene pursuant to an agreement and plan of merger and reorganization ( the “ merger agreement ” ) , dated january 18 , 2017 , among private altimmune , pharmathene , its wholly owned acquisition subsidiaries mustang merger sub corp i inc. ( “ merger sub corp ” ) and mustang merger sub ii llc ( “ merger sub llc ” ) . pursuant to the merger agreement , merger sub llc agreed to acquire 100 % of the outstanding capital stock of private altimmune in a reverse triangular merger and reorganization pursuant to section 368 ( a ) of the internal revenue code ( the “ mergers ” ) . prior to the mergers , pharmathene was a publicly traded biodefense company engaged in phase 2 clinical trials in developing sparvax-l , an anthrax vaccine . on may 4 , 2017 , private altimmune and pharmathene closed the mergers in accordance with the terms of the merger agreement . upon the closing of the mergers , ( i ) merger sub corp merged with and into private altimmune , with private altimmune remaining as the surviving corporation ; ( ii ) private altimmune then merged with and into merger sub llc , with merger sub llc ( renamed as “ altimmune llc ” ) remaining as the surviving entity ; and ( iii ) pharmathene was renamed as “ altimmune , inc. ” in accordance with the terms of the merger agreement , pharmathene issued 0.0249702 ( the “ share exchange ratio ” ) of a share of pharmathene common stock for each share of private altimmune common stock outstanding as of the closing date . all historical share and per share information — including common stock , convertible preferred stock , redeemable preferred stock , common stock warrants , restricted stock , and stock options — has been retroactively adjusted to reflect the impact of the share exchange ratio . in addition , private altimmune stock options and warrants were also replaced with options and warrants to purchase pharmathene 's common stock at the same exchange ratio of 0.0249702. immediately prior to closing , 19,976 shares of our convertible preferred stock were converted into private altimmune common stock on a 1-for-1 basis . story_separator_special_tag the duration , costs and timing of clinical trials and development of our product candidates will depend on a variety of factors , including : scope , rate of enrollment and expense of our ongoing , as well as any additional , clinical trials , and other research and development activities ; significant and potentially changing government regulation ; and the timing and receipt of regulatory approvals , if any . a change in the outcome of any of these variables with respect to the development of a product candidate could mean a significant change in the costs and timing associated with the development of that product candidate . for example , if the fda , or another regulatory authority were to require us to conduct clinical trials beyond those that we currently anticipate will be required for the completion of clinical development of a product candidate , we could be required to expend significant additional financial resources and time on the completion of clinical development . 65 we plan to increase our research and development expenses for the foreseeable future as we continue the development of clinical and preclinical candidates . our current planned research and development activities include the following : complete an extension study of the participants in the recently completed phase 2a trial of nasovax monovalent influenza vaccine to measure further durability of immune response ; additional development of nasovax for the treatment of pandemic influenza , contingent on non-dilutive funding from barda or other governmental agencies ; pre-clinical development of alt-702 , a tlr 7/8 cancer immunostimulant ; commence a phase 2 clinical trial for heptcell for the treatment of chronic hepatitis b ; development of complementary immunotherapy programs for which we are currently evaluating acquisition and partnership targets ; complete the investigation for potential causes contributing to the less-than-expected immunogenicity observed in our phase 1 clinical trial for nasoshield anthrax vaccine . the results of these investigations are expected to be completed in the first half of 2019 , and ; manufacture clinical trial materials in support of our clinical trials . to date , a significant portion of our research and development efforts have been related to the development of nasovax , nasoshield , sparvax-l , and heptcell product candidates . we do not allocate personnel-related costs , costs associated with our general research platform improvements , depreciation or other indirect costs to specific programs . general and administrative expenses general and administrative expenses consist primarily of salaries and related costs for personnel , including stock-based compensation and travel expenses for our employees in executive , operational , finance and human resource functions . other general and administrative expenses include facility-related costs and professional fees for directors , accounting and legal services , and expenses associated with obtaining and maintaining our intellectual property . we anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support our continued research and development activities . we also anticipate increased expenses related to audit , legal , regulatory and tax-related services associated with maintaining compliance with exchange listing and the sec requirements , director and officer insurance , investor relations costs and other costs associated with being a public company . additionally , if and when we believe a regulatory approval of the first product candidate appears likely , we anticipate an increase in staffing and related expenses as a result of our preparation for commercial operations , especially as it relates to the sales and marketing of our product candidates . critical accounting policies and significant judgment and estimates our management 's discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements , which have been prepared in accordance with u.s. generally accepted accounting principles . the preparation of our consolidated financial statements requires us to make judgments and estimates that affect the reported amounts of assets , liabilities , revenues , and expenses , and the disclosure of contingent liabilities in our consolidated financial statements . we base our estimates on historical experience , known trends and events , and various other factors that we believe to be reasonable under the circumstances . actual results may differ from these estimates under different assumptions or conditions . on an ongoing basis , we evaluate our judgments and estimates in light of changes in circumstances , facts , and experience . the effects of material revisions in estimates , if any , will be reflected in the consolidated financial statements prospectively from the date of change in estimates . while our significant accounting policies are described in more detail in the notes to our consolidated financial statements appearing elsewhere in this annual report , we believe the following accounting policies used in the preparation of our consolidated financial statements require the most significant judgments and estimates . 66 business combination we use our best estimates and assumptions to assign fair value to the tangible and intangible assets acquired and liabilities assumed at the acquisition date . our estimates are inherently uncertain and subject to refinement . during the measurement period , which may be up to one year from the acquisition date , we may record adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed , with the corresponding offset to goodwill . in addition , uncertain tax positions and tax-related valuation allowances are initially established in connection with a business combination as of the acquisition date . we collect information and reevaluates these estimates and assumptions quarterly and records any adjustments to our preliminary estimates to goodwill during the measurement period . upon the conclusion of the measurement period or final determination of the fair value of assets acquired or liabilities assumed , whichever comes first , any subsequent adjustments are recorded to our consolidated statements of operations and comprehensive loss . amounts paid for acquisitions are allocated to the tangible assets acquired

liquidity and capital resources overview our primary sources of cash , cash equivalents , and restricted cash for the year ended december 31 , 2018 were $ 37.4 million in net proceeds received from the issuance of common stock and common units . our primary source of cash during the comparable period in 2017 was $ 3.0 million in net proceeds received from the issuance of the notes , $ 13.7 million in cash assumed from the mergers , and $ 13.0 million in net proceeds from the issuance of the redeemable preferred stock and existing warrants . our cash , cash equivalents , and restricted cash were $ 34.4 million at december 31 , 2018. we believe , based on the operating cash requirements and capital expenditures expected for 2019 , our cash on hand at december 31 , 2018 , and revenue from our government sponsored contracts , are sufficient to fund operations for at least a 12-month period from the date our consolidated financial statements are expected to be issued . we have not generated any revenues from the sale of any products to date , and there is no assurance of any future revenues from product sales . our sources of revenue consist of revenues under our contract with barda and niaid for the development of nasoshield and sparvax-l , respectively , and to a lesser degree from other licensing arrangements . we have incurred significant losses since we commenced operations . as of december 31 , 2018 , we had accumulated losses of $ 116.9 million since our inception . in addition , we have not generated positive cash flows from operations . we have had to rely on a variety of financing sources , including the issuance of debt and equity securities . as capital resources are consumed to fund our research and development activities , we may not have sufficient capital to fund our plan of operations .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```liquidity and capital resources overview our primary sources of cash , cash equivalents , and restricted cash for the year ended december 31 , 2018 were $ 37.4 million in net proceeds received from the issuance of common stock and common units . our primary source of cash during the comparable period in 2017 was $ 3.0 million in net proceeds received from the issuance of the notes , $ 13.7 million in cash assumed from the mergers , and $ 13.0 million in net proceeds from the issuance of the redeemable preferred stock and existing warrants . our cash , cash equivalents , and restricted cash were $ 34.4 million at december 31 , 2018. we believe , based on the operating cash requirements and capital expenditures expected for 2019 , our cash on hand at december 31 , 2018 , and revenue from our government sponsored contracts , are sufficient to fund operations for at least a 12-month period from the date our consolidated financial statements are expected to be issued . we have not generated any revenues from the sale of any products to date , and there is no assurance of any future revenues from product sales . our sources of revenue consist of revenues under our contract with barda and niaid for the development of nasoshield and sparvax-l , respectively , and to a lesser degree from other licensing arrangements . we have incurred significant losses since we commenced operations . as of december 31 , 2018 , we had accumulated losses of $ 116.9 million since our inception . in addition , we have not generated positive cash flows from operations . we have had to rely on a variety of financing sources , including the issuance of debt and equity securities . as capital resources are consumed to fund our research and development activities , we may not have sufficient capital to fund our plan of operations .
```    
 Suspicious Activity Report : this combination of serum antibody , mucosal antibody and t-cell responses provides the potential for improved ability to prevent infection and suggests that nasovax could have a greater impact on flu symptoms and containing the spread of the flu virus than currently approved influenza vaccines . all subjects were followed for an additional six months after vaccination to assess the durability of the antibody response , and 8 of the 15 subjects from the highest dose returned between 12 and 14 months after initial dosing for an additional immunogenicity assessment . these new nasovax data on the long-term durability of the immune response show that the immune response elicited by nasovax remained at seroprotective levels for at least 13 months . durable responses on the order of one year are not expected from currently approved influenza vaccines and suggest that the immune response induced by nasovax could be much longer than the current influenza vaccines . 61 nasoshield nasoshield is an anthrax vaccine designed to provide rapid and stable protection after a single intranasal administration . in a head-to-head comparison with the existing approved anthrax vaccine in well-established animal models , a single dose of nasoshield showed complete protection from inhalation anthrax and was non-inferior to multiple doses of the existing approved anthrax vaccine while providing for a more rapid and stable immune response . we have developed the product candidate with the support of the biomedical advanced research and development authority ( “ barda ” ) , and with their continued financial and contractual support , we launched a phase 1 trial of nasoshield in the first quarter of 2018. the purpose of the phase 1 trial was to assess the safety and immunogenicity of a single intranasal dose of nasoshield at four dose cohort levels . an additional cohort received a repeated dose of nasoshield at day 21. based on initial data from the single and two-dose cohorts , nasoshield was well-tolerated but did not produce an appreciable toxin neutralizing antibody ( tna ) response . the company did not expect this result given the compelling nonclinical data obtained previously in two well-established animal models for anthrax . we are investigating all potential causes that may have contributed to these results . the results of these investigations are expected in the first half of 2019. sparvax-l sparvax-l is our alternative anthrax vaccine candidate being developed under contract with niaid . it is a recombinant protein-based anthrax vaccine designed to require fewer doses and have a longer shelf-life than the only currently licensed anthrax vaccine . the shelf life of a liquid formulation was insufficient to meet the government standards and the product was reformulated as a lyophilized ( dry powder ) formulation . we have demonstrated a significant improvement in product stability ( at least two years at room temperature and at least six years at refrigerated temperatures ) with the lyophilized formulation . recent preclinical experiments have shown sparvax-l to be 100 % protective with a two-dose regiment ( 0 and 14 days ) with higher protective toxin neutralizing antibodies than the currently licensed vaccine administered under the same schedule . as of december 31 , 2018 , development activities under the existing niaid contract are substantially complete and the company will only continue development of sparvax-l with the support of the us government or other entity . no such funding has been identified as of the date of this filing . merger with pharmathene our business is the result of a merger between pharmathene , inc. ( “ pharmathene ” ) and the business previously known as altimmune , inc. ( “ private altimmune ” ) . in may 2017 , private altimmune merged with pharmathene pursuant to an agreement and plan of merger and reorganization ( the “ merger agreement ” ) , dated january 18 , 2017 , among private altimmune , pharmathene , its wholly owned acquisition subsidiaries mustang merger sub corp i inc. ( “ merger sub corp ” ) and mustang merger sub ii llc ( “ merger sub llc ” ) . pursuant to the merger agreement , merger sub llc agreed to acquire 100 % of the outstanding capital stock of private altimmune in a reverse triangular merger and reorganization pursuant to section 368 ( a ) of the internal revenue code ( the “ mergers ” ) . prior to the mergers , pharmathene was a publicly traded biodefense company engaged in phase 2 clinical trials in developing sparvax-l , an anthrax vaccine . on may 4 , 2017 , private altimmune and pharmathene closed the mergers in accordance with the terms of the merger agreement . upon the closing of the mergers , ( i ) merger sub corp merged with and into private altimmune , with private altimmune remaining as the surviving corporation ; ( ii ) private altimmune then merged with and into merger sub llc , with merger sub llc ( renamed as “ altimmune llc ” ) remaining as the surviving entity ; and ( iii ) pharmathene was renamed as “ altimmune , inc. ” in accordance with the terms of the merger agreement , pharmathene issued 0.0249702 ( the “ share exchange ratio ” ) of a share of pharmathene common stock for each share of private altimmune common stock outstanding as of the closing date . all historical share and per share information — including common stock , convertible preferred stock , redeemable preferred stock , common stock warrants , restricted stock , and stock options — has been retroactively adjusted to reflect the impact of the share exchange ratio . in addition , private altimmune stock options and warrants were also replaced with options and warrants to purchase pharmathene 's common stock at the same exchange ratio of 0.0249702. immediately prior to closing , 19,976 shares of our convertible preferred stock were converted into private altimmune common stock on a 1-for-1 basis . story_separator_special_tag the duration , costs and timing of clinical trials and development of our product candidates will depend on a variety of factors , including : scope , rate of enrollment and expense of our ongoing , as well as any additional , clinical trials , and other research and development activities ; significant and potentially changing government regulation ; and the timing and receipt of regulatory approvals , if any . a change in the outcome of any of these variables with respect to the development of a product candidate could mean a significant change in the costs and timing associated with the development of that product candidate . for example , if the fda , or another regulatory authority were to require us to conduct clinical trials beyond those that we currently anticipate will be required for the completion of clinical development of a product candidate , we could be required to expend significant additional financial resources and time on the completion of clinical development . 65 we plan to increase our research and development expenses for the foreseeable future as we continue the development of clinical and preclinical candidates . our current planned research and development activities include the following : complete an extension study of the participants in the recently completed phase 2a trial of nasovax monovalent influenza vaccine to measure further durability of immune response ; additional development of nasovax for the treatment of pandemic influenza , contingent on non-dilutive funding from barda or other governmental agencies ; pre-clinical development of alt-702 , a tlr 7/8 cancer immunostimulant ; commence a phase 2 clinical trial for heptcell for the treatment of chronic hepatitis b ; development of complementary immunotherapy programs for which we are currently evaluating acquisition and partnership targets ; complete the investigation for potential causes contributing to the less-than-expected immunogenicity observed in our phase 1 clinical trial for nasoshield anthrax vaccine . the results of these investigations are expected to be completed in the first half of 2019 , and ; manufacture clinical trial materials in support of our clinical trials . to date , a significant portion of our research and development efforts have been related to the development of nasovax , nasoshield , sparvax-l , and heptcell product candidates . we do not allocate personnel-related costs , costs associated with our general research platform improvements , depreciation or other indirect costs to specific programs . general and administrative expenses general and administrative expenses consist primarily of salaries and related costs for personnel , including stock-based compensation and travel expenses for our employees in executive , operational , finance and human resource functions . other general and administrative expenses include facility-related costs and professional fees for directors , accounting and legal services , and expenses associated with obtaining and maintaining our intellectual property . we anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support our continued research and development activities . we also anticipate increased expenses related to audit , legal , regulatory and tax-related services associated with maintaining compliance with exchange listing and the sec requirements , director and officer insurance , investor relations costs and other costs associated with being a public company . additionally , if and when we believe a regulatory approval of the first product candidate appears likely , we anticipate an increase in staffing and related expenses as a result of our preparation for commercial operations , especially as it relates to the sales and marketing of our product candidates . critical accounting policies and significant judgment and estimates our management 's discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements , which have been prepared in accordance with u.s. generally accepted accounting principles . the preparation of our consolidated financial statements requires us to make judgments and estimates that affect the reported amounts of assets , liabilities , revenues , and expenses , and the disclosure of contingent liabilities in our consolidated financial statements . we base our estimates on historical experience , known trends and events , and various other factors that we believe to be reasonable under the circumstances . actual results may differ from these estimates under different assumptions or conditions . on an ongoing basis , we evaluate our judgments and estimates in light of changes in circumstances , facts , and experience . the effects of material revisions in estimates , if any , will be reflected in the consolidated financial statements prospectively from the date of change in estimates . while our significant accounting policies are described in more detail in the notes to our consolidated financial statements appearing elsewhere in this annual report , we believe the following accounting policies used in the preparation of our consolidated financial statements require the most significant judgments and estimates . 66 business combination we use our best estimates and assumptions to assign fair value to the tangible and intangible assets acquired and liabilities assumed at the acquisition date . our estimates are inherently uncertain and subject to refinement . during the measurement period , which may be up to one year from the acquisition date , we may record adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed , with the corresponding offset to goodwill . in addition , uncertain tax positions and tax-related valuation allowances are initially established in connection with a business combination as of the acquisition date . we collect information and reevaluates these estimates and assumptions quarterly and records any adjustments to our preliminary estimates to goodwill during the measurement period . upon the conclusion of the measurement period or final determination of the fair value of assets acquired or liabilities assumed , whichever comes first , any subsequent adjustments are recorded to our consolidated statements of operations and comprehensive loss . amounts paid for acquisitions are allocated to the tangible assets acquired

