After Anwar S Proposal Health Dg Explains Unknowns In Single Dose Strategy

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Health Ministry director-general Dr Noor Hisham Abdullah said the long-term efficacy of administering a single dose of Pfizer-BioNTech Covid-19 vaccine is unknown.
This is after opposition leader Anwar Ibrahim yesterday proposed the government delay the second dose shot and instead use them as the first dose to cover more people.
The government began administering the second dose today, which is 21 days after the first dose, in line with the World Health Organization's (WHO) recommendations.
While not mentioning Anwar, Noor Hisham (photo, above) explained that the third phase of the clinical trial had shown that the vaccine could achieve efficacy of 89 percent after 14 to 21 days of the first dose.
However, Noor Hisham said the study didn't have data about relying on a single dose for the long-term.
"At the moment, the long-term efficacy of administering a single dose of Corminaty is not known because the recipients in the clinical trial all received their second dose between 19 and 42 days.
"It is important to note that a drastic increase in antibodies that can provide long-term efficacy is after the second dose.
"A delay in the second dose could slow the production of optimum antibodies," he said in a statement.
Corminaty is the name of the Pfizer-BioNTech vaccine.


The WHO's strategic advisory group of experts on immunisation recommends the second dose to be administered between 21 and 28 days.
However, a delay of up to 42 days is allowed.
The clinical trial found that after the second dose, the efficacy was at 94.6 percent.
Some scientists have argued for delaying the second dose if there is a shortage of vaccines as the first dose already provides substantial protection in the near term.
In their analysis of a separate study published in the New England Journal of Medicine, two researchers found the first dose of Pfizer-BioNTech vaccine provided 68.5 percent efficacy after seven days.
This increased to 92.6 percent after 14 days from receiving the first dose, according to Danuta M Skowronski of the British Columbia Centre for Disease Control and Gaston De Serres of the Institut National de Santé Publique du Québec, both in Canada.
"With such a highly protective first dose, the benefits derived from a scarce supply of vaccine could be maximised by deferring second doses until all priority group members are offered at least one dose," they said in a letter, also published in the New England Journal of Medicine.
However, both researchers acknowledged the uncertainty surrounding the duration of protection with a single dose.
"But the administration of a second dose within one month after the first, as recommended, provides little added benefit in the short term, while high-risk persons who could have received a first dose with that vaccine supply are left completely unprotected," they said. - Mkini

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