MUMBAI: The Chinese Covid-19 vaccine has an unlikely USP over others: A tiny label that can monitor heat damage.
The label, better known as vaccine vial monitor, has been a part of mass vaccination such as polio drives in India because it has a heat-sensitive chemical that tells health workers if a vial was stored correctly or damaged due to exposure to heat. It is the easiest way to find out if the cold chain to store certain vaccines was maintained or not.
“As India steps up vaccination, especially in rural parts, the vaccine vial monitor would be the best tool to indicate if a vial is usable or not,” said Dr Sunil Khaparde, former central health ministry official who was associated with the Pulse Polio drive in the initial days.
Vaccinators in India are trained to check the ‘bindi’ mark before giving vaccines to children. In 1998, VVMs were first used in the oral polio vaccine and Dr Khaparde said he believes they played a role in helping eradicate polio. “While India had 1,934 cases in 1998, the use of VVMs coincided with a drop since 1999 when 1,126 cases were reported,” said Dr Khaparde.
On July 14, Temptime, the American company licensed by the World Health Organisation to manufacture VVMs, wrote to India’s health minister Mansukh Mandaviya about using VVM for Covid vaccines available in India. “The people of India have benefited from the use of VVM in the universal immunization programme for over 20 years. VVM’s ability to indicate heat damage to vaccines, is a critical enabling tool in the immunization programme,” said the letter.
At the moment, the World Health Organisation has not made it mandatory for Covid vaccines to have VVMs. “It is preferred, but not mandatory as per the WHO norms,” said a doctor from the state health department. Most governments currently are focused on getting vaccines and not on VVMs, he added.
BMC executive health officer Dr Mangala Gomare said at present Covid vaccines have to be used within four hours of opening the vial. “With such a recommendation, there is no fear of heat affecting the vaccine stability,” she said. Each vial can vaccinate 10 to 20 people as per the manufacturer.
“VVM applied to Covid vaccines will make it far easier to re-distribute vaccines from areas of low to high utilization/demand, by referring to the VVM, supply chain managers can be confident that the vaccine has, to-date, been stored appropriately, facilitating the acceptance of vaccine shipments both across and within states,” said the Temptime letter to Mandaviya. According to the letter, the overall cost impact of VVM is just 0.3% of the Covid-19 vaccine vial cost. “Hence, the cost impact of VVM is minimal as compared to the benefits,” the letter concluded.