The COVID-19 pandemic: it was the dominant topic for two years but seemed to disappear from the headlines due to the war in Ukraine, rising prices and the climate crisis. However, the incidences are rising sharply again. Are we already in the middle of the summer wave? How much protection will the vaccines adapted to Omicron offer? And who should get a fourth vaccination? "The fourth shot makes sense for older people," says Ulrich Elling from the IMBA - Institute of Molecular Biotechnology of the Austrian Academy of Sciences (OeAW). And adds: "It's urgent - the wave is coming now."
SUMMER WAVE
Why are the incidences rising again now?
Ulrich Elling: First of all, community immunity has been waning again for some time. To be able to maintain community immunity in Austria, if we assume immunity lasts for a year, an average of 25,000 people would have to be infected every day. Secondly, we are dealing with the new Omicron variant BA.5, which can better circumvent the immune protection. People who have recovered from BA.1 can now become infected again. The third point is that our behavior has changed.
Has the Omicron variant BA.5 already triggered a summer wave?
Elling: BA.5 has been the dominant variant in Austria since June 7 and infections have been rising steeply since then. The famous R number, which says how many people get infected from one person, is 50 percent higher for BA.5 than for BA.2. That means the proportion has more than doubled per week. This is a dynamic that speaks for a considerable summer wave.
According to the WHO, there is a four percent increase in hospitalizations.
COURSE OF BA.5
Can you already say something about the course of BA.5?
Elling: There is still little data on the course of the virus. But there are a few clues: one of the mutations in BA.5 is known from Delta. According to the WHO, there is a four percent increase in hospitalizations. But all this is still very imprecise. Increased hospitalizations are being reported in Israel and higher death tolls are being reported in Portugal. In France, data have been presented showing that the symptoms are more pronounced again. But it's not about how the virus behaves; rather how we are protected and who gets sick. The first Omicron wave hit us right after a booster campaign. Thus, older vaccinated people were relatively well protected. This protection against infection is now de facto non-existent. It can therefore be assumed that a disproportionately large number of older people will become infected.
How well will a vaccine adapted to Omicron protect?
Elling: The approval is not there yet, but Moderna has submitted laboratory data. There is a scale from which you can measure the concentration of the neutralizing antibodies. The vaccine used to date has a value in the range of 5,000 to 6,000 against the wild-type variants, but only 1,400 against Omicron. The vaccine adapted to Omicron has a value of 2,400. That means we are better protected, but we are nowhere near where we were. What's more, this vaccine was made against BA.1. As we know, BA.5 bypasses infection with BA.1. Accordingly, the adapted vaccine only achieves values of 700 to 1,000 against BA.5.
It's urgent - the wave is coming now
NEW VACCINATION
Who should get a fourth jab with the current vaccines?
Elling: Getting vaccinated now to secure your summer vacation is not feasible because the current vaccines do not protect against infection. But for older and immunocompromised people, a refresher is worth it. There is very clear data from Israel that has shown that hospitalizations are reduced by a factor of three. Data from Portugal also show that the fourth shot makes sense for older people. But it's urgent – the wave is coming now.
How much protection does someone who has been vaccinated three times and infected once with BA.2 have?
Elling: In people who became infected with BA.2, the disease was not that long ago, so the immunity should hold for now. Plus, BA.2 and BA.5 are very similar and only differ in a few positions in the spike protein. BA.1, however, is almost a different serotype compared to the other Omicron versions, where infection with one hardly protects against infection with the other.
It makes no sense to use a potentially fatal disease to build up immunity to a potentially fatal disease.
COMEBACK OF MASKS IN SUMMER?
Will we have to wear masks again this summer?
Elling: It is a political decision whether we will wear masks or not. The disease is no less dangerous in the summer than in the fall. The only advantage is that it doesn't overlap with the influenza wave. According to the data from the Prognosis Consortium, the summer wave will have a dampening effect on the autumn wave. But that's only true if the autumn variant is related to BA.5! In any case, it makes no sense to use a potentially fatal disease to build up temporary immunity against a potentially fatal disease. A new US study that is still under review examined the risk of hospitalization for second and third infections in US veterans. The result: people who are infected for the second time have an even higher risk of being hospitalized than those who are infected for the first time. In a nutshell, it is best if everyone is infected as infrequently as possible – and vulnerable people not at all.