More and more Poles are already behind the second dose of the COVID-19 vaccine. However, this does not mean that fully vaccinated people become immune immediately. How soon after the second dose of the vaccine does immunity to coronavirus appear and how can we check if we are safe?

Four COVID-19 vaccines are currently registered in Poland . One of them - the preparation from Johnson & Johnson - is a single dose vaccine. With this vaccine, protection starts on day 14 after vaccination and full immunity starts on day 28 after vaccination.

The other three preparations, namely the Pfizer BionTech, Moderna and AstraZeneca preparations, are two-dose vaccines - the second dose of the vaccine is administered at an interval of about 6 weeks (in the case of Pfizer and Moderna) to about 12 weeks (AstraZeneca).

We gain partial immunity to infection after the first dose of the vaccine. However, we will be properly protected only after the completion of the entire vaccination cycle, i.e.after taking the second dose.But not immediately - immunity will appear only some time after taking the preparation.

COVID-19 Vaccine Effectiveness

Although vaccines are safe and effective, none of them protect against the disease one hundred percent. What does it look like in the case of individual preparations, in accordance with the information contained in the Summary of Product Characteristics?

  • Comirnaty Pfizer / BioNTech Vaccine- the first dose of the preparation provides protection at the level of 69%. (12 days after vaccination). After the second dose of the vaccine, the effectiveness in preventing COVID-19 is almost 95%.
  • COVID-19 Vaccine Moderna . The company did not provide data on the effectiveness of the vaccine after the first dose. After the second dose, its effectiveness is 94.1%.
  • Vaxzevria AstraZenecavaccine - the first dose of the vaccine provides 60% protection. (which occurs approximately 3 weeks after vaccination), the effectiveness after the second dose is 82.4%. (with the recommended interval of 12 weeks between the 1st and 2nd doses). If the vaccine is given earlier, the effectiveness will be lower - for example with a second dose given beforeafter 6 weeks, protection is 54.9%.
  • Vaccine Janssen (Johnson & Johnson) COVID-19 Vaccine . The effectiveness of this single-dose vaccine is estimated at approx. 67%.

How quickly does immunity develop after the second dose of the vaccine?

Many people vaccinated with the second dose feel that it is safe to revert to pre-pandemic behavior immediately after vaccination. However, it is not so. Immunity induced by vaccination will not appear until some time after full vaccination.

The minimum time needed to build up immunity after the second dose of vaccine is as follows:

  • with the Pfizer BioNTech vaccine - 7 days
  • with Moderna vaccine - 14 days
  • with AstraZeneca vaccine - approx. 15 days

Only after this time has elapsed we will be properly protected.

How to check the immunity after the second dose of the vaccine?

A person vaccinated against COVID-19 can check if they are already immune by testing for antibodies - these are serological tests that assess IgG antibodies against the S protein.

Such tests are paid, but you do not need a referral and can be performed in most diagnostic laboratories. The most reliable are quantitative tests in which the presence of antibodies and their concentration (level) are determined. Other options are qualitative and semi-quantitative testing.

Category:

COVID 19