The COVID-19 pandemic has emerged as the most significant public health emergency in this century. As individuals around the globe race for treatment options and take preventive measures against COVID-19, those living in the Southern Hemisphere are also preparing for another virus – seasonal influenza. The flu typically takes hold from April through September in the Southern Hemisphere and impacts service members and their beneficiaries on military orders in places south of the equator, such as New Zealand, Australia, southern parts of Africa and South America as well as Indonesia.
Before 2020, a Federal Drug Administration-approved Southern Hemisphere influenza vaccine was not available for military personnel or beneficiaries. Service members received the Northern Hemisphere flu vaccine during the Northern Hemisphere season, which runs October to March.
Once the FDA approved a Southern Hemisphere influenza vaccine, the combatant commands quickly engaged with the Office of Assistant Secretary of Defense for Health Affairs’ Health Readiness Policy and Oversight and Defense Health Agency to get access for their personnel.
Through joint efforts by the CCMDs, Defense Logistics Agency, U.S. Army Medical Materiel Agency, and DHA’s Immunization Healthcare Division, service members and their beneficiaries in the Southern Hemisphere can access the FDA-approved, U.S.-labeled Southern Hemisphere vaccine Fluzone®.
“The vaccination will be made available at designated medical treatment facilities in May 2020,” according to Tara Reavey, chief of policy and program management for DHA's Immunization Healthcare Division.
Access to both Northern and Southern hemisphere influenza vaccines supports troop readiness since different flu strains circulate in each hemisphere. “Symptoms of the Northern Hemisphere and Southern Hemisphere seasonal influenzas are similar,” said Dr. Jay Montgomery, medical director of the Immunization Healthcare Division’s North Atlantic Region Vaccine Safety Hub. “Typical flu symptoms include fever, cough, sore throat, runny nose, and muscle aches, but in severe cases may result in hospitalization or death.”
However, Montgomery added, “the common strains identified in the Northern and Southern Hemisphere differ about 60% of the time.” He said the challenge to support force readiness became apparent as DoD members experienced flu-like symptoms when traveling to the Southern Hemisphere flu zone after receiving the Northern Hemisphere vaccine.
“Obviously if we don't have the right virus strains in the vaccine, people are not going to get protection against those strains,” said Montgomery. “Over the years, a substantial number of influenza-like illnesses have occurred among service members and other DoD personnel participating in multinational exercises, such as in Australia, every year,” he said, adding that a vaccine targeting Southern Hemisphere influenza should result in a decrease of influenza-like illnesses there.
The DHA-Interim Procedures Memorandum 20-002 for Southern Hemisphere influenza was published March 20 and “aligns with Centers for Diseases Control and Prevention recommendations to use the appropriate influenza vaccine,” said Reavey. Specifically, Southern Hemisphere influenza vaccination is required for all active duty, reserve component, National Guard members (and recommended for all other beneficiaries), permanently or temporarily assigned for at least 14 contiguous days between April 1 and Sept. 30 to an area designated as a Southern Hemisphere influenza zone by the World Health Organization.
U.S. government civilian employees and family members of personnel who are living in or conducting a permanent change of station to the Southern Hemisphere are authorized to receive the Southern Hemisphere vaccine. In order to develop adequate immunity, personnel traveling to the Southern Hemisphere between April and September should be vaccinated at least two weeks before they go to the region, if possible.
DoD personnel traveling to or residing in the Northern Hemisphere for at least 14 days between October and March and who have not received the current seasonal Northern Hemisphere influenza vaccine are required to receive a Northern Hemisphere vaccine in accordance with the most current DHA-IPM for the Northern Hemisphere seasonal influenza vaccination program.
The DHA-IPM states that individuals may receive vaccines for both the Northern Hemisphere flu and the Southern Hemisphere flu in a year span, but the immunizations will need to be given at least 28 days apart. Service members will not need to receive a flu vaccine for either hemisphere when traveling to the area during an offseason and if in the region for less than 14 days.
For more information on the Southern Hemisphere influenza vaccine, please visit the Military Health System Influenza webpage.