Pfizer jab 95% effective – study

TWO DOSES: SIGNIFICANTLY INCREASES IMMUNITY

Researchers not able to study effect of SA variant.

The largest real-world study yet of the Pfizer-BioNTech vaccine on Thursday confirmed that the jab provided more than 95% protection against Covid-19, but found that the level dropped significantly when people received just one of the two prescribed doses.

The authors of the research from Israel’s national vaccination campaign said it showed real-world proof that the pandemic could be ended by rapid, global vaccination programmes.

An analysis of public health data from Israel – one of the countries with the highest proportion of fully vaccinated adults

– showed the vaccine was extremely effective in protecting even elderly individuals at a time when the more infectious English variant was dominant, according to the results published in the Lancet medical journal.

By the start of April, nearly five million people in Israel had received two doses of the PfizerBioNTech jab, more than 70% of the population.

The study found that two doses conveyed 95.3% protection against infection and 96.7 protection against death seven days after the second dose. After 14 days, that protection increased to 96.5% and 98%, respectively.

But the protection was considerably lower when people received just a single vaccine dose.

Between seven and 14 days after the first dose, protection against infection was found to be 57.7% – and protection against death 77%.

The authors said that one dose may provide a shorter window of protection, especially in an environment where new viral variants emerge.

“Importantly, the study shows that two doses of the vaccine significantly increase levels of immunity and protection,” said Jonathan Ball, professor of molecular virology at the University of Nottingham, who was not involved in the research. “This is why it is important people get both doses.”

During the analysis period, there were 232 268 confirmed Covid-19 infections, and nearly 95% of samples tested were found to be the English B117 variant.

There were 4 481 severe infections and 1 113 deaths.

The team behind the research said they were not able to study the effect of the South African variant, which has also been identified in Israel.

Before Thursday, the largest real-world study of the PfizerBioNTech vaccine, also in Israel, was nearly five times smaller, involving 1.2 million people.