The new Covid-19 Omicron vaccines are tailored to better match circulating strains of the virus and are expected to offer “broader protection”, according to the latest recommendations from the National Immunization Advisory Committee (NIAC).
But the advice to the Department of Health added that their impact on future variants was “unpredictable”.
The HSE will shortly introduce the new updated bivalent vaccines – one version protecting against the BA.1 form of Omicron and the other covering BA.4 and BA.5, the dominant strains here.
Niac said the Covid-19 booster shot results in a high level of protection against serious diseases that is sustained for four months or more.
If someone was vaccinated and also had the infection, the protection was “even more permanent,” it said.
The number of patients hospitalized with Covid-19 has risen to 328 – the highest in many weeks.
Of these patients, 16 were in the ICU, a slight increase in two weeks.
The seven-day positivity rate for people with PCR tests has risen to 12 percent from 10 percent two weeks ago.
The Niac Advice, which expects infections to rise this fall and winter, said limited data from clinical trials of BA.1 Covid-19 vaccines shows similar responses to the first shot, but long-term follow-up data is unavailable .
“Due to the limited number of participants in the studies, very rare side effects cannot be ruled out. Myocarditis and pericarditis are considered very rare risks of mRNA vaccination, especially in men under 30 years of age after the second dose of the primary series,” said Niac.
“However, the risk is lower after booster doses.”
The experts said data from clinical trials show that the neutralizing antibody levels after bivalent BA.1 vaccines compared to the original vaccines are similar to those of the first Wuhan strain of Covid-19 and higher than those of the Omicron variants, including BA.1, BA. 2, BA.2.75 and BA.5.
“While antibody levels against BA.5 are higher than those achieved with the original vaccines, they are lower than those against the other variants.”
They said: “In two small pre-clinical studies, antibody levels against BA.5 were higher after vaccination with a BA. 4-5 bivalent vaccine than BA.1 vaccines”.
It is not known to what extent the higher antibody levels induced by the adapted vaccines will increase protection against the disease variant Covid-19.
“The higher antibody levels against BA.5 are expected to provide clinically meaningful benefit, particularly for those who are at risk at this time when BA.5 is dominant,” Niac added. “Current evidence suggests that the bivalent vaccines offer similar or better protection than the original vaccines.
“It is expected that additional protection against disease variants can be provided.”
As people wonder whether they should wait for the updated vaccines, Niac stressed that a timely booster shot is more important than the vaccine given.
The original vaccine offers significant protection against hospitalization, serious illness and death.
If the new vaccines are scarce, the original booster vaccination should be offered.
https://www.independent.ie/irish-news/health/covid-19-advice-new-updated-omicron-jabs-are-expected-to-offer-broader-protection-42018799.html Covid-19 Advice: New updated Omicron shots expected to offer ‘broader protection’