Can pneumococcal vaccines backfire?

In a popular online post, Peter McCullough claims that a new study found people who got pneumococcal vaccines were more likely to get pneumonia and die than people who didn’t get the vaccine.

A group of scientists in Spain looked at the health records of more than 2.2 million adults aged 50 and older. They wanted to see if two vaccines (PCV13 and PPSV23) helped prevent people from being hospitalized with pneumonia. These vaccines are meant to protect against  Streptococcus pneumoniae, a type of bacteria that can cause serious pneumococcal disease, including lung infections like pneumonia.

The study spanned one year, 2019 and compared people who had gotten one of the pneumonia vaccines with those who hadn’t. The researchers checked how many people in each group were hospitalized for pneumonia and how many died while in the hospital.

At first glance, the people who had gotten the vaccine seemed more likely to end up in the hospital with pneumonia. But the scientists explained why this happened: the vaccinated people were usually older and had more health problems than those who were not vaccinated. That’s probably why they got vaccinated in the first place. In other words, they were already at a higher risk of getting sick.

After the researchers adjusted their numbers to try to account for those differences, the vaccines still didn’t appear to lower the chance of pneumonia hospitalizations. However, the study did not show that the vaccines caused pneumonia or made people more likely to die. It only showed that the vaccines did not seem to be very effective at preventing pneumonia in that particular group and year.

The authors were very clear: their study does not prove that the vaccines are harmful. Instead, it shows that in this group of older adults in Catalonia, Spain, the vaccines didn’t seem to make a big difference in preventing hospital stays for pneumonia. The scientists said the results might be affected by other factors, like age, health conditions, and the types of pneumonia germs going around at that time.

They also pointed out that newer vaccines (PCV15, PCV20, and PCV21) are now being used and might work better. The researchers believe that vaccine effectiveness should be checked again in the future, using these newer versions.

Even though the names sound alike, pneumococcal disease and pneumonia are not the same thing. Pneumococcal disease is caused by certain bacteria and can lead to different kinds of illnesses. Pneumonia is just one of those illnesses, along with blood infections, infections of the lining of the brain, ear infections, and sinus infections. Other bacteria, viruses, or health problems can also cause pneumonia.

It looks like this study shows that pneumonia vaccines increase the risk of getting pneumonia or dying, but that is not true. The study never said that vaccines cause harm. It only found that, in this one population, the vaccines didn’t prevent as many pneumonia hospitalizations as hoped. Scientists still agree that pneumonia vaccines are safe and can help protect people, especially older adults and those with health problems.