The Food and Drug Administration (FDA) said on Monday, Dec. 13, coronavirus disease (COVID-19) booster shots depend on the vaccine brand administered in the primary series.
This in reply to the question during a Laging Handa press briefing on the possibility of shortening the interval between the primary series and the booster shot from the original six months for two-dose vaccines.
“Depende ito sa vaccine brand na natanggap mo as primary series ‘no. So, iyon pong Janssen at saka po iyong Sputnik Light na mga single dose, ang advice po natin diyan ay three months after magbigay na po ng booster (This depends on the vaccine brand you received as a primary series. For Janssen and Sputnik Light which are single dose, our advice is three months before giving the booster shot),” FDA Director General Eric Domingo said.
“Pero iyon pong mga ibang two-dose vaccines katulad po ng Sinovac, AstraZeneca, Pfizer, Moderna, nakikita po natin na nag-uumpisa lamang naman na mag-wane iyong protection at the six months kaya dito po ibinibigay ang booster shot (As for two-dose vaccines like Sinovac, AstraZeneca, Pfizer and Moderna, we have seen that protection starts to wane after six months that is why boosters are given at this time),” he added.
Dr. Rontgene Solante, chief of the Adult Infectious Diseases and Tropical Medicine Unit of San Lazaro Hospital, also echoed this statement during an interview on DZMM where he said that protective efficacy of vaccines start to go down at the fifth and sixth month, and once a booster dose was administered, it starts to increase again based on the so-called neutralizing antibody titer.
He said that based on the data, it is optimal to have the booster shot after six months rather than having it earlier since after four months the protection that the vaccine provides remains strong. What should be studied, according to Solante, is to determine the best interval in administering booster shots that will maximize the efficacy of the vaccines.
He also made the exception to Janssen, a single-dose vaccine which has shown lesser efficacy after three months yet he stated that the rest of the COVID-19 vaccines still provide good protection after the third or fourth month.