JEDDAH — The Ministry of Health has reaffirmed the safety of the mixing of vaccines approved in the Kingdom as it is based on the international research and findings of specialized research committees. The ministry emphasized that this procedure has been approved by the World Health Organization as well as from the concerned authorities in several countries around the world. Last June, Saudi Arabia's National Scientific Committee for Infectious Diseases gave its approval for using different COVID-19 vaccines for the first and second dose. "The approval is in accordance with international scientific studies that showed the possibility of giving two doses of two different coronavirus vaccines safely and effectively in fighting the virus, with the effectiveness of which the second dose aims to achieve," the ministry said. Mixing COVID-19 vaccines is emerging as a good way to get people the protection they need when faced with safety concerns and unpredictable supplies. Results announced on Monday by a UK group suggest that the combination sometimes outperforms two shots of the same vaccine. Meanwhile, a Spanish study released on May 18 showed that the presence of neutralizing antibodies rose sevenfold after people who already received the first shot of AstraZeneca vaccine were given the Pfizer dose, significantly more than the doubling effect observed after a second AstraZeneca shot. Another study in Germany found that mixing vaccines was better at inducing an immune response than giving two AstraZeneca shots. Overall, the incidence of any systemic reaction was less common after the mixed series.
