Fever, headache, dizziness, and nausea are the most common side effects of the “mix and match” vaccine approach of using Sinovac then AstraZeneca shots, according to the Thailand’s Public Health Ministry.

The method of using Sinovac as the first dose, followed by an AstraZeneca shot as the second, 3-4 weeks apart, is now Thailand’s main vaccination practice, which helps shorten the gap between two doses of AstraZeneca, now about 3 months, but with similar levels of efficacy, according to the ministry.

As of September 8^th, China’s Sinovac vaccine accounts for most of the shots administered, at 15.78 million doses, followed by 16.15 million doses of AstraZeneca, 4.6 million doses of Sinopharm and 917,540 doses of Pfizer-BioNTech.

For those inoculated with Sinovac, the most common side effects are dizziness (20.82%), nausea (14.14%), headache (13.85%), vomiting (12.86%), fatigue (9.08%), muscle pain (6.64%), rashes (6.14%), loose stools (5.56%), fever (4.60%) and feeling slightly feverish (4.02%).

The most common side effects from AstraZeneca are fever (26.52%), headaches (24.98%), dizziness (20.48%), nausea (18.95%), vomiting (18.22%), fatigue (15.22%), muscle pain (14.01%), loose stools (8.92%), feeling slightly feverish (7.35%) and rashes (4.24%).

As for Sinopharm, the most common side effects are dizziness (18.83%), headache (15.58%), vomiting (14.29%), nausea (13.64%), fever (8.44%), fatigue (7.79%), muscle pain (7.79%), rashes (6.49%), itchiness (5.19%) and loose stools (4.55%).

The most common side effects from Pfizer are fever (20.59%), headache (17.65%), vomiting (17.65%), nausea (14.71%), dizziness (14.71%), muscle pain (8.82%), loose stools (8.82%), fatigue (4.41%) and dyspepsia (2.94%).

It is also found that 24 people who received Sinovac experienced severe allergies (which accounts for 0.16 per 100,000 doses), while only 6 people who received AstraZeneca experienced them (which accounts for 0.04 per 100,000 doses).

The most common side effects of two doses of Sinovac and AstraZeneca as a third booster shot, are headache, fever, nausea, muscle pain and vomiting.

Meanwhile, the most common side effects of two doses of Sinovac and Pfizer as a third booster shot are fever, vomiting, headache, nausea and dizziness.

Five people who received the AstraZeneca vaccine experienced VITT (Vaccine-Induced Immune Thrombotic Thrombocytopenia), three of them died and two recovered, said Dr. Chakkarat Pittayawong-anont, Director of the Epidemiology Division of the Disease Control Department.

Those with VITT will experience severe headaches, numbness in the arms or legs, facial palsy, trouble breathing, swollen legs, severe stomach aches or bleeding. Those who received AstraZeneca and experience any of these symptoms within 4-30 days must see the doctor and must bring their first vaccine booking appointment.