Live Attenuated Vaccine for Polio

The disease

The polio disease (poliomyelitis) is an infectious disease caused by the poliovirus, which is one of the intestine viruses’ group. The virus is transmitted from one person to another, following contact with secretions (usually feces but also respiratory secretions). Once the virus enters the digestive system, it multiplies and is excreted in the feces. In most cases of infection (80%-90%), there are no symptoms of illness. In 10% to 20% of cases, the disease manifests with symptoms such as fever, headache, stomachache, nausea, vomiting, or throat ache. In rare cases, the disease leads to meningitis.

The most alarming phenomenon, which occurs in less than 1% of cases, is the occurrence of paralysis due to the spread of the virus from the digestive system through the bloodstream to the body, resulting in damage to the nervous system. Paralysis occurs more frequently in the lower limbs and may be accompanied by severe muscle pain. Additionally, the severity of the paralysis depends on the number of infected nerve cells.

There is no cure for polio, and the paralysis resulting from the disease is permanent. The only solution is prevention through vaccination. Additionally, it is imperative to follow hygiene rules, particularly to wash hands thoroughly with soap and water for about 20 seconds after using the bathroom, before handling food, and after changing a baby’s diaper.

The influence of the vaccine in Israel: in 1957, Israel incorporated the inactivated polio vaccine, which prevents morbidity, into the routine vaccination program. In 1961, a live attenuated vaccine, which also prevents polio spread, was added. The last reported case of polio occurred in 1988, with 16 cases of paralysis. In 2005, a decision was made to discontinue the use of the live attenuated vaccine. However, due to a resurgence of polio cases, its administration was reinstated in 2013.

In February 2022, a case of circulating vaccine-derived poliovirus type 3 (cVDPV3) was confirmed. The virus, secreted in the feces where it multiplies, underwent a genetic change. When a live attenuated virus reaches an unvaccinated population, it may cause illness among unvaccinated individuals. Sewage findings indicated widespread transmission of this variant. A national campaign administering both inactivated and live attenuated vaccines successfully halted the spread, and no additional paralysis cases have been reported since then.

In June 2022, a circulating vaccine-derived poliovirus type 2 (cVDPV2) was confirmed in sewage in the Jerusalem area. This type of virus spreads to numerous areas in Israel, from the Golan Heights in the north, to Be'er Sheva in the south.

The incidence of polio in Israel is related to similar cases around the world. Recent years have seen a rise in polio cases, affecting various regions, including African countries, the United Kingdom, Canada, and the United States. Consequently, vaccination today goes beyond safeguarding against a transient threat - it becomes an investment in future protection and peace of mind.

• Fever: you can administer an analgesic to help relieve pain and reduce fever.
• Vomiting and diarrhea: continue breastfeeding, offer water in a spoon slowly.

Further information about vaccine side effects