Corona: Strong vaccination reactions can indicate a good immune response

For people with risk factors such as diabetes, high blood pressure or heart disease, a booster corona vaccination is recommended. However, the fact that unpleasant vaccination reactions such as headaches, fatigue and sometimes even a slight fever can occur after a corona vaccination unsettles some people.

The fact that there are such vaccination reactions, which are often referred to as side effects, is generally not a bad sign. Because they show that the body directs strength and energy into the immune system in order to build up a defense against the coronavirus. This has now been confirmed by a current study from the University of California in San Francisco.

The vaccination reactions of over 360 people were examined

For the so-called “Building Optimal Antibodies Study” (BOOST), the scientists examined the effects of primary immunization with the mRNA vaccines BNT162b2 (Biontech/Pfizer) and mRNA-1273 (Spikevax from Moderna) in more detail.

To do this, 363 adults were asked to fill out a questionnaire every evening for the first six days after the two vaccination doses about the symptoms they experienced that day. Some also wore a finger ring at night that recorded skin temperature and heart rate.

Reactions consistently stronger after second dose

Their result: The systemic reactions were overall stronger after the second dose.

75.5 percent complained of fatigue (versus 54.2 percent after the first dose)
54.8 percent reported muscle pain (versus 31.6 percent after the first dose)
53.0 percent reported headaches (versus 27.1 percent after the first dose)
40.3 percent reported feeling unwell (versus 18.4 percent after the first dose)
Heart rate, heart rate variability and skin temperature also responded more strongly to the second dose.

Four symptoms show strong immune response

To find out whether the strong vaccination reactions are associated with a better protective effect, the researchers compared the symptoms with the concentration of neutralizing antibodies after one and six months.

The result: A strong vaccination reaction is associated with a higher number of antibodies after the second vaccination (1.4 to 1.6 times) – but only with four symptoms:

chills
fatigue
malaise
Headache

For the other ten symptoms queried (muscle pain; joint pain; nausea; fever; swollen lymph nodes; pain/swelling of the injection site; pain/swelling of the arm that was not vaccinated; allergic reaction; abdominal pain; others) the connection was not clear (not significant ).

Do you need a refresher on your corona vaccination?

Because people with high blood pressure are more likely to become seriously ill with Covid-19 and have an increased risk of death. The World Health Organization (WHO) points this out. Older people and people with previous illnesses are particularly affected by high blood pressure. The Standing Vaccination Commission at the Robert Koch Institute (RKI) recommends a corona booster vaccination for this risk group. Hypertension patients should therefore discuss with their doctor whether a revaccination is an option for them.

Better protective effect through vaccination reaction

The study shows: Strong vaccination reactions were associated with an increase in neutralizing antibodies for both mRNA vaccines examined – and thus with a better protective effect against the coronavirus.

Overall, the number of antibodies increases by ten percent with each additional symptom. People who suffer from multiple “side effects” after vaccination are very likely to have better protection against infection.

However, there are two limitations: Firstly, local symptoms at the injection site, such as pain at the injection site, had no influence on the antibody response. On the other hand, the connection between vaccination reaction and antibody number could not be determined after the first vaccination.