"We appeal to all the people of Kenya to avoid taking this vaccine."
On the other hand, he endorsed alternative treatments for the virus, including steam inhalation and hydroxychloroquine - methods that have not been approved by the World Health Organization.
"There are drugs that have been repurposed and used effectively to treat COVID-19. We also know that vaccination for this disease is totally unnecessary making the motivation suspect."
In 2019, Dr Karanja opposed the vaccination of schoolgirls against the Human Papillomavirus (HPV).
He claimed it was unnecessary because it affected those "whose lifestyle involves irresponsible sexual behaviours".
In 2014, he gained attention for opposing the government's rollout of a tetanus vaccine and claimed it was a sterilising campaign against women.