BEIJING, Jan. 20 (Xinhua) -- As an increasing number of countries started mass vaccination, gaps in access to COVID-19 vaccines, especially huge disparities between the developed world and developing world, have become glaringly evident.

While the three wealthy economies of the United States, Britain and the European Union "have given citizens about 24 million doses so far -- more than half of the shots administered globally -- vast numbers of countries have yet to begin their campaigns," Bloomberg News reported on Monday.

Disparities in immunity "pose a threat to both have and have-not states," the news outlet warned.

"Giving the coronavirus an opportunity to advance and generate new mutants would have significant economic and public-health consequences, adding to the pain as the death toll surpasses 2 million," it said.

More worryingly, opening the 148th session of the World Health Organization's (WHO) Executive Board, WHO chief Tedros Adhanom Ghebreyesus on Monday warned of the moral consequences of the lack of COVID-19 vaccines for poorer countries, saying that the higher-income countries are privileged compared to the developing countries.

"More than 39 million doses of vaccine have now been administered in at least 49 higher-income countries. Just 25 doses have been given in one lowest-income country. Not 25 million, not 25,000, just 25," he said.

Similarly, UN Secretary-General Antonio Guterres on Monday called for solidarity with developing countries in the context of COVID-19 and pre-existing inequalities and injustices.

Vaccines must be a global public good, available to everyone, everywhere, he said.

The good news is that China has, on various occasions, pledged continuous efforts in global COVID-19 response.

"We were the first to pledge to make vaccines a global public good, bearing in mind the greater good of humanity," Chinese State Councilor and Foreign Minister Wang Yi said recently.