WorldThe 3rd injection is the Pfizer vaccine, what are the side effects?

The 3rd injection is the Pfizer vaccine, what are the side effects?

The Oxford University study found that of those who received the first dose of AstraZeneca and the second dose of Pfizer, about 78% experienced fatigue, compared with 53% of those who received two doses of Pfizer.

Meanwhile, about 65% of study participants experienced headaches when mixing AstraZeneca with Pfizer. Other symptoms such as joint pain, fever, and muscle aches are also present in similar proportions.

Covid-19 vaccination site in Pennsylvania, USA

In general, the side effects do not last long, usually only about 2 days.

The above study did not consider the impact of the third dose, the booster dose of the vaccine. However, it also shows that if the same vaccine is used for the third dose, the side effects may be less than switching to another vaccine if the two vaccines are different in technology.

Despite the potential for side effects, the benefits of getting the 3rd shot are real. A study by the UK Health Security Agency (UKHSA), recently published, found that 2 weeks after a booster dose of Pfizer, protection from infection was 93.1% in patients those who had previously received AstraZeneca injections and 94% for Pfizer.


Although there are no data on protection against hospitalization or death after the third dose, Professor Wei Shen Lim of the UK Joint Committee on Immunization and Immunization thinks the rate is probably even higher than 93 per cent.

Overall, the most common side effects of the third injection were fever, headache, fatigue, and pain at the injection site. However, most of these manifestations are mild or moderate. Some people also experience symptoms such as diarrhea, vomiting, and muscle and joint pain, according to the Centers for Disease Control and Prevention (CDC).

In addition, some people who received dose 3 reported axillary lymphadenopathy. But this is not a cause for concern, because swollen lymph nodes are a normal sign that the body is building a defense against corona virus.

However, those who do not feel any symptoms after the injection need not worry. The NPR news site quoted epidemiology professor Charlotte Baker as saying that if you don’t see side effects, that doesn’t mean the vaccine isn’t effective, it’s just that “your body’s reaction just doesn’t show up.” .