Covid-19 booster shot needed within 270 days of primary dose to maintain 'fully vaxxed' status

Approximately nine months.

Fasiha Nazren | January 05, 2022, 06:10 PM

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Persons aged 18 years and above who have completed a primary vaccination series should receive a booster dose of an mRNA vaccine no later than 270 days after the last dose in the primary vaccination series.

This is as recommended by the Expert Committee on Covid-19 Vaccination (EC19V) said the Ministry of Health (MOH) in a press release on Jan. 5, 2022.

This will also apply to individuals who received recognised non-mRNA primary vaccination regimens offered under the National Vaccination Programme as well as regimens of other WHO EUL vaccines.

For this group, however, most will not be due for a booster shot for some time.

MOH said that it will expect non-mRNA vaccine Novavax to be available as an option by then.

Fully vaccinated only for 270 days

From Feb. 14, 2022 onwards, a person will be considered as fully vaccinated only for 270 days (approximately nine months) after the last dose in their primary vaccination series, provided that they are:

  • Persons aged 18 years and above who have completed the primary vaccination series of Covid-19 vaccines
  • Eligible for booster vaccination

MOH said that these people should receive their booster shots from around five months thereafter and no later than 270 days thereafter, to ensure an optimal level of protection.

Upon receiving the booster, individuals will continue to be considered fully vaccinated beyond the 270 days.

Example

If a person completed their primary vaccination series on June 1, 2021, they would be eligible for a booster shot five months later (Nov. 1 onwards).

They would have to receive their booster shot by Feb. 26, 2022 in order to continue to be considered fully vaccinated.

No boosters for vaccinated recovered Covid-19 persons

At this point in time, vaccinated persons who have recovered from Covid-19 do not require an additional booster dose.

However, recovered persons who were unvaccinated or partially vaccinated before their infection should receive one dose of the mRNA vaccine (or two doses if they are taking Sinovac-CoronaVac vaccine) at least three months after infection to be considered as fully vaccinated.

The 270-day vaccination validity period does not apply to recovered persons who complete this vaccination requirement.

Substantial protection against Omicron variant

According to the release, vaccination, especially boosters, retain substantial protection against severe disease for Covid-19 and against the Omicron variant.

The protection from the primary series vaccination wanes with time and is substantially reduced six months after the last dose in the primary vaccination series.

International data has also shown that protection against Omicron variant from a primary vaccination series is weaker compared to that against the Delta variant, while boosters increase the protection against infection and severe illness from Omicron.

Top image from Hor Teng Teng.

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