Researchers surprised
Thanks to Corona: That’s why many people are receiving a new flu vaccine
Updated 11/20/2024 – 9:48 a.mReading time: 2 min.
For years there has been a recommendation to use a quadruple vaccine to protect against the flu. This does not apply to the current season. This is the reason.
Some people may have already been surprised: from this season onwards, a triple vaccine is recommended for the flu vaccination instead of the previous quadruple vaccine. It offers protection against just three instead of four influenza virus strains. This is not a cost-cutting measure, but is due to a marginal effect of the Corona measures: ”We have completely eradicated a flu strain,” says Carsten Watzl from the TU Dortmund. “This shows very clearly how effective the measures were.”
Until 2018, a triple vaccine was standard in Germany. Since the 2018/2019 flu season, a quadruple vaccine has been recommended by the Standing Vaccination Commission (Stiko). For the beginning of the season, the triple vaccine was recommended again as standard flu protection – without antigens against the B Yamagata flu strain.
As early as 2020, experts had determined that this group of influenza viruses was no longer circulating. B Yamagata did not appear again in the years that followed, says immunologist Watzl. According to an article in the specialist magazine ”Lancet”, B Yamagata is the only virus that causes respiratory diseases that was made extinct in the course of the corona pandemic – although caution is still advised: not every corner of the world is well monitored, B Yamagata may have it after all survived somewhere.
The World Health Organization (WHO) concluded in September 2023 that the B-Yamagata component is no longer needed for vaccination protection. The so-called trivalent vaccine should now only contain antigens from one influenza B strain (B Victoria) and two influenza A strains. Different variants of these subtypes circulate worldwide, with varying degrees of intensity in each flu season.
Every February, the WHO considers how the vaccines for the coming season should be designed to provide the best possible protection. Since it is difficult to predict which strains will dominate, quadruple vaccination protection against two A and two B strains has been used for years. This increases the likelihood that the vaccine will be effective against the strains that are actually circulating.
The flu is a highly contagious infectious disease. The course is much more severe than “flu-like infections,” as colds caused by other pathogens are often called. Fatigue, high fever and a dry cough usually occur suddenly. In Germany, tens of thousands of people fall ill with influenza in the winter months.
Influenza viruses reduce the body’s defenses and make the body susceptible to life-threatening complications: According to the RKI, influenza-related deaths are usually caused by bacterial pneumonia after the influenza viruses have previously damaged the lungs. The number of deaths varies greatly from season to season – from several hundred to over 25,000, as in the 2017/18 season.
Stiko recommends an annual vaccination in the fall for people aged 60 and over or if there is an increased health risk, for example as a result of an underlying illness. A vaccination does not offer 100% protection against illness, but it does ensure milder symptoms. Antibiotics, on the other hand, are ineffective against influenza, as with all diseases caused by viruses. However, they are used when complications caused by bacteria also occur.
– What are the main differences between the new trivalent flu vaccine and the previous quadrivalent version?
Interview between Time.news Editor and Immunologist Carsten Watzl on the New Flu Vaccine Guidelines
Time.news Editor: Good morning, Carsten! Thank you for joining us today. There’s been quite a bit of buzz surrounding the change in flu vaccination recommendations. Can you explain why, starting this flu season, a triple vaccine is now preferred over the quadruple vaccine?
Carsten Watzl: Good morning! Thank you for having me. Yes, it’s quite fascinating. The shift back to a triple vaccine isn’t a cost-cutting measure but stems from the impact of the COVID-19 measures we implemented over the past few years. During the pandemic, we inadvertently eradicated the B Yamagata flu strain, which was one of the components in the previous quadruple vaccine. This change in the landscape of circulating viruses prompted health officials to adapt the vaccine accordingly.
Editor: That’s astonishing! So, you’re saying that COVID-19 measures had such a profound effect on flu viruses?
Carsten Watzl: Absolutely. It’s remarkable how effective the measures were. Prior to the pandemic, B Yamagata was a common influenza strain, but since 2020, we’ve seen that it no longer circulates. According to an article in the Lancet, it’s actually the only respiratory disease virus that has been completely wiped out due to these measures.
Editor: Interesting! Does this mean people should be concerned about other strains that might not have been completely monitored?
Carsten Watzl: While our monitoring systems are robust, we can’t guarantee that every contagion has been accounted for globally. There’s always a chance that the B Yamagata could resurface from a less-monitored area. Caution is advised, but as things stand, the B Yamagata component is no longer needed for the vaccination.
Editor: So, the World Health Organization (WHO) also weighed in on this, correct? What did they conclude?
Carsten Watzl: Exactly. In September 2023, the WHO determined that the B-Yamagata component is unnecessary for effective vaccination. The new trivalent vaccine will now feature antigens from one B strain—B Victoria—and two A strains instead. This adjustment is based on epidemiological data and aims to provide the best possible protection against the predominant strains each season.
Editor: It seems like this new recommendation is quite strategic. How does the WHO decide on the composition of the flu vaccine each year?
Carsten Watzl: Every February, WHO looks at global surveillance data to predict which strains are most likely to circulate in the upcoming flu season. Given the ever-changing nature of influenza viruses, this process is quite complex. They analyze which strains were most dominant in the southern hemisphere before our flu season begins to inform their recommendations.
Editor: It’s clear that adapting to the virus is an ongoing challenge. So, for individuals planning to get vaccinated this season, what should they consider?
Carsten Watzl: They should be aware that flu strains can differ in severity and prevalence each year. Getting vaccinated with the updated trivalent vaccine is crucial to ensure protection against the current circulating strains. It’s also important for individuals, especially those at higher risk, to stay informed about flu activity and discuss vaccination plans with their healthcare provider.
Editor: Thank you, Carsten, for your insights. It seems like we’re witnessing a significant transformation in public health strategies due to the pandemic.
Carsten Watzl: Thank you for having me! Yes, indeed. The pandemic has reshaped how we view and manage respiratory viruses, and it will be important for us to continue to adapt as new data emerges.
Editor: Absolutely. We appreciate your expertise on this topic!