The Kaiser Permanente Vaccine Study Center in Oakland, California - which carried out a new study of Merck's cervical-cancer vaccine Gardasil - has found that the vaccine is not linked to any serious health problems, though it might lead to fainting on the vaccination day, as well as skin infections a fortnight or so later.

With the Gardasil vaccine - which protects against four strains of the human papillomavirus (HPV) - linked to some mild side-effects like fainting and skin problems such as redness and inflammation at the jab site, it has been recommended to the doctors that they should ask the patients sit or lie down for 15 minutes after vaccination.

The Merck-funded Gardasil study was sought by the US Food and Drug Administration (FDA) and the European Medicines Agency, so as to ascertain the safety of the vaccine in a large group of people.

For the study, the researchers - led by Nicola Klein, the co-director of the vaccine-study center at Kaiser - observed emergency-room visits and hospitalizations for two months after each shot of Gardasil vaccine; and also analyzed medical records pertaining to deaths and some other conditions such as autoimmune diseases like lupus, Type 1 diabetes, rheumatoid arthritis, and multiple sclerosis.

With the researchers not finding any notable increased risk of health problems linked to Gardasil, Mary Anne Jackson - from Children's Mercy Hospitals and Clinics in Kansas City, Mo. - said that the findings of the study are "very reassuring," and added: "The bottom line is it's a very safe vaccine."