Do COVID-19 and its vaccine affect male fertility?

Written by:

Dr Tan Kok Kuan

Dr Tan Kok Kuan

Dr Tan is a medical doctor in private practice focusing on men's health, and a contributing author of the Singapore HIV PrEP prescribing guidelines and the Blueprint to end AIDS and HIV transmission in Singapore by 2030. Read more of his articles at


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The short answer to this is yes. There have been a number of studies detailing how COVID-19 causes inflammation of the testes, resulting in a reduction in the number of sperm produced, as well as an increase in the DNA damage in the sperm.

Some studies also reported a decrease in sperm motility and well as increased permutations in the size and shape of sperm.

An article published very recently in March 2021 of 43 men who recovered from COVID-19 found that 25% of them had a reduced sperm count as well as sperm that was of poorer morphology (size and shape). This was in spite of the fact that there was no viral genetic material detected in the semen. Also, the men who had a more severe COVID-19 infection also had poorer sperm count and quality.

Another review paper published slightly later in Jan 2021 referencing 57 other papers concluded that COVID-19 infection does cause testicular injury and inflammation and alters sperm parameters. In fact, the paper stated that COVID-19 infection can cause inflammation of the testes to a point as to cause pain in the scrotum. It further concluded that COVID-19 infection reduces the number of sperm produced and also caused more DNA damage in the sperm.

Another study published by a Chinese team in Nov 2020 also found that patients who recovered from COVID-19 had a lower sperm count and poorer sperm morphology. They also found evidence of damage to the testes by the immune system as triggered by COVID-19.

What about the vaccine?

A small Israeli study involving 43 men found that the Pfizer-BioNtech COVID-19 vaccine had no effect on sperm parameters. This is a small study so although promising, more data would be needed to verify this finding. Also, this finding cannot be extrapolated to the other COVID-19 vaccines.

Most of the evidence available point to the fact that a COVID-19 infection can cause inflammation of the testes and negatively affect sperm parameters. So yes, COVID-19 infection can affect male fertility. For young men who have been infected with COVID-19 and are planning to start a family, they may want to speak to their doctors about undergoing a semen analysis.

This post, first published on Dr Tan’s blog, has been edited for length and clarity.