An antiviral stockpile is a reserve supply of essential antiviral medications in case of shortage. Many countries have chosen to stockpile antiviral medications against pandemic influenza. Because of the time required to prepare and distribute an influenza vaccine, these stockpiles are the only medical defense against widespread infection for the first six months. The stockpiles may be in the form of capsules or simply as the active pharmaceutical ingredient, which is stored in sealed drums and, when needed, dissolved in water to make a bitter-tasting, clear liquid.

There are no evidence-based guidelines to guide the use of these stockpiled drugs, and plans are based on assumed similarities to seasonal influenza. The most common antivirals are neuraminidase inhibitors, which, if begun during the first 48 hours after symptoms appear, will reduce the duration of seasonal influenza by about one day. Taken before symptoms appear, it may prevent disease in about three-quarters of people treated prophylactically. Currently, this is recommended in institutionalized elderly people and other high-risk groups as a form of post-exposure prophylaxis during seasonal influenza outbreaks. However, since pandemic influenza differs somewhat from normal seasonal influenza, it is not clear that these drugs will prove either safe or effective for their intended purpose.

For a person who has very recently been exposed to seasonal influenza, effective post-exposure prophylaxis generally requires taking a drug like oseltamivir for seven to ten days, at half the daily dose needed for treatment. A person that is repeatedly exposed, such as hospital staff members, may require continuous treatment throughout the duration of the outbreak in a community. Based on experience with seasonal influenza in nursing homes, control of influenza requires full treatment of any ill persons and prophylactic treatment of all their contacts. In a pandemic situation, before a vaccine becomes available, this level of treatment and medical prevention may require providing drugs to 80% of the people in an affected community. Consequently, very large supplies of the drugs must be made available — much larger supplies than could be produced on demand. Stockpiles are generally arranged in advance by government health authorities, due to fear of shortages and an awareness of manufacturing limitations during an outbreak.

Supplies in each country

List of available treatments of antiviral per country.

Rank Country / Territory Population Treatments Date Last Updated Source 1 1,337,722,000 2 3 50,000,000 April 27, 2009 Bloomberg.comReport of antiviral stockpile sales 4 230,014,115 5 6 166,146,000 7 162,221,000 8 154,729,000 9 141,833,393 10 127,630,000 47,700,000 November 27, 2017 Ministry of Health, Labour and Welfare 11 109,610,000 12 92,226,600 13 88,069,000 14 82,062,200 15 79,221,000 16 76,030,000 17 71,517,100 18 70,495,782 19 66,020,000 20 65,073,482 21 63,389,730 22 61,612,300 30,000,000 April 28, 2009 BBC News Swine flu: How serious a threat? 23 60,090,400 24 50,020,000 25 48,697,000 26 48,333,000 21,100,000 August 21, 2009 The Korea Times More Flu Virus Vaccines to Be Stockpiled 27 46,143,700 28 45,853,000 29 44,830,423 30 43,739,000 31 42,272,000 32 39,802,000 33 39,745,613 34 38,130,300 35 34,895,000 36 33,476,688 1,400,000 April 27, 2009 Bloomberg.com Report of Antiviral Stockpile Sales 37 32,710,000 38 31,394,044 39 30,747,000 40 29,331,000 41 29,165,000 42 28,685,400 43 28,200,000 44 28,150,000 45 27,488,000 46 25,721,000 47 23,906,000 48 23,837,000 49 23,580,000 50 23,027,672 51 22,894,000 52 21,906,000 53 21,745,000 54 21,496,700 55 21,075,000 56 20,238,000 57 19,625,000 58 19,522,000 59 18,498,000 60 950,000 June 6, 2009 Ministerio de Salud de Chile Nueva Influenza Humana A (H1N1) 61 16,508,734 62 15,757,000 63 15,571,506 64 15,290,000 65 15,263,000 66 14,027,000 67 13,938,115 68 13,388,910 69 13,010,000 70 12,935,000 71 12,534,000 72 12,523,000 73 11,262,500 74 11,206,000 75 11,204,000 76 10,741,000 3,000,000 1 Jan. 2007 Influenza 77 10,631,800 78 10,474,600 79 10,327,800 80 10,090,000 81 10,069,000 82 10,033,000 83 10,029,900 84 9,998,000 85 9,863,000 86 9,850,000 87 9,690,000 88 9,264,000 89 9,133,000 90 8,935,000 91 8,629,900 92 8,356,700 93 8,303,000 94 7,705,800 95 7,602,100 96 7,466,000 97 7,411,000 98 6,952,000 99 6,732,000 100 6,619,000 101 6,420,000 102 6,349,000 103 6,320,000 104 6,316,000 105 6,163,000 106 5,743,000 107 5,696,000 108 5,511,451 109 5,482,000 110 5,411,100 111 5,333,089 112 5,110,000 113 5,073,000 114 4,839,400 500,000 April 28, 2009 Referenced. Confirmation expected. 115 4,814,075 1,400,000 April 28, 2009 116 4,599,000 117 4,579,000 3,000 April 28, 2009 Nacion.com (Spanish) 118 4,517,800 119 4,432,000 120 4,422,000 121 4,382,100 122 4,306,500 123 4,224,000 124 (US) 3,982,000 125 3,955,000 126 3,767,000 127 3,761,646 128 3,683,000 129 3,572,700 130 3,454,000 131 3,361,000 132 3,350,400 133 3,291,000 134 3,230,100 135 3,170,000 136 2,985,000 137 2,845,000 138 2,719,000 139 2,671,000 140 2,259,400 141 2,171,000 142 2,067,000 143 2,053,355 144 2,048,900 145 1,950,000 146 1,705,000 147 1,611,000 148 1,475,000 149 1,409,000 150 1,340,341 151 1,339,000 152 1,288,000 153 1,185,000 154 1,134,000 155 864,000 156 849,000 157 801,600 158 791,000 159 762,000 160 697,000 161 676,000 162 676,000 163 624,000 164 523,000 165 520,000 166 513,000 167 506,000 168 491,700 169 412,600 170 400,000 171 342,000 172 319,326 173 309,000 174 307,000 175 256,000 176 240,000 177 (Netherlands) 198,000 178 179,000 179 (US) 178,000 180 172,000 181 163,000 182 111,000 183 (US) 110,000 184 109,000 185 (Netherlands) 107,000 186 104,000 187 104,000 188 98,000 189 (US) 89,300 190 88,000 191 (US) 87,000 192 86,000 193 84,000 194 (UK) 80,000 195 67,000 196 (US) 67,000 197 (UK) 65,000 198 62,000 199 (UK) 61,811 200 (Denmark) 57,000 201 (UK) 56,000 202 52,000 203 (Denmark) 48,797 204 35,700 205 33,000 206 (UK) 33,000 207 30,800 208 (UK) 31,000 209 (UK) 23,000 210 (New Zealand) 20,000 211 20,000 212 (UK) 15,000 213 10,000 214 10,000 215 (UK) 6,600 216 (UK) 5,900 217 (UK) 3,000 218 (New Zealand) 1,500 219 (New Zealand) 1,400 220 800 221 (UK) 50

References