The latest on the coronavirus pandemic and vaccines

The United States has reported at least 2,463 cases of coronavirus variants that were first spotted in the United Kingdom, South Africa and Brazil, according to the US Centers for Disease Control and Prevention. 

The CDC warned that these figures don't represent the total number of such cases circulating nationwide -- just those that have been detected by analyzing positive samples.

The UK variant: The vast majority of these cases, 2,400, are the more contagious variant known as B.1.1.7, which was originally detected in the UK. This variant has been found in 44 states, Puerto Rico and Washington, DC. About a quarter are in Florida.

South Africa variant: There are 53 cases of the B.1.351 variant, first seen in South Africa, reported in 15 states and Washington, DC. 

Brazil variant: Lastly, 10 cases of the P.1 variant first linked to Brazil have been discovered in five US states.

India's Prime Minister Narendra Modi received his first dose of a Covid-19 vaccine on Monday, kicking off the second phase of the country's immunization campaign.

He received India's home-grown vaccine, Covaxin, at the All India Institute of Medical Sciences (AIIMS) in Delhi.

The second phase: This next part of the vaccination drive will allow shots for those aged 60 years and older, and those aged above 45 with serious medical conditions.

The first phase had been targeted at healthcare and frontline workers, but vaccines will now available to the general public within the age bracket.

India has distributed more than 14.3 million vaccines since the program began on January 16, according to the Indian Ministry of Health.

The Indian Ministry of Health has recorded more than 11 million cases to date, and more than 157,000 related deaths.

Mexican President Andres Manuel Lopez Obrador is expected to ask US President Joe Biden to share some of the Covid-19 vaccine supply on Monday, according to a Mexican government official briefed on plans for the conversation.

The two leaders are due to hold a virtual bilateral meeting on Monday.  

What the collaboration could look like -- a purchase agreement, donation, or loan -- is undefined, the official told CNN.

The first step is to ask whether the United States is willing to cooperate, the source said.  

Mexico has purchase agreements in place for hundreds of millions of vaccine doses with different vaccine makers around the world, the large majority of which have yet to be fulfilled.

It has also purchased vaccine supplies from both Russia and China, but it hasn't received any vaccines directly from the US, its most important ally and largest trading partner.   

Pfizer, an American company, has shipped Covid-19 vaccines to Mexico -- but they were produced in European laboratories and have arrived in relatively limited supply.   

As of Sunday evening, Mexico reported having administered just under 2.5 million doses of coronavirus vaccines. 

The United States reported 51,204 new Covid-19 cases and 1,097 related deaths on Sunday, according to a tally by Johns Hopkins University.

That raises the national total to at least 28,605,669 cases and 513,091 deaths since the pandemic began.

The totals include cases from all 50 states, the District of Columbia and other US territories, as well as repatriated cases.  

Vaccination drive: At least 96,402,490 vaccine doses have been distributed and at least 75,236,003 doses have been administered, according to the US Centers for Disease Control and Prevention Vaccine. 

At least 49,772,180 people have received one or more doses of the vaccine and at least 24,779,920 people have received two doses.