A recent study published in eClinicalMedicine has found that the Sabin strain-derived inactivated poliovirus vaccine (sIPV) demonstrates immune persistence for at least 10 years after vaccination. The researchers compared the immune response of sIPV to wild poliovirus seed strains (wIPV) against current and wild poliovirus strains.
The study builds on a previous phase III clinical trial in China, which showed the effectiveness of sIPV in infants. The three-dose primary vaccination provided protection, and the booster dose further increased the levels of neutralizing antibodies (nAbs). However, the persistence of these antibodies after completing the sIPV vaccination regimen was unclear.
To investigate this, the researchers analyzed serum samples from children who had received either sIPV or wIPV between 2012 and 2014. They measured the nAb titers against poliovirus types 1, 2, and 3 using a microneutralization assay.
The results showed that both sIPV and wIPV induced persistent immunity for a minimum of 10 years after vaccination. The protective rates and nAb titers against poliovirus types 1, 2, and 3 were similar between the two groups. However, the levels of nAbs varied over time, with a decline at four years post-vaccination. Nevertheless, the decrease in nAb levels slowed down between the ages of 6 and 10 years.
The study concluded that both sIPV and wIPV are effective in providing long-term immunity against poliovirus. These findings support the potential use of attenuated Sabin strains in preparing inactivated poliovirus vaccines.
This research has implications for the eradication of poliomyelitis, particularly in developing countries. Vaccines with high immune persistence, like sIPV, could play a crucial role in achieving this goal.
Source: eClinicalMedicine (No URLs, and image source: Smile Studio AP/Shutterstock.com)
